The invention relates generally to apparatus for cleaning swimming pools, toilets and the like, and more particularly to methods and apparatus for producing biocidal solutions for killing microorganisms in bodies of water.
Control of algae and bacteria growths in swimming pools is a serious problem. Most modern swimming pools are heated, exposed to sunlight and are substantially closed recirculating systems, making them an ideal place for algae to grow. Users of such pools introduce coliform (E. coli) and other bacteria into the pool water. They also shed skin and hair in the pool water, and occasionally urinate in the pool, providing a fertile environment for bacteria to multiply rapidly. Thus, it is necessary to control the growth of both algae and bacteria in swimming pools. Conventionally, this requires the addition of large amounts of chlorine to the pool. However, the chlorine tends to burn the swimmers' eyes, particularly if used in quantities sufficient to suppress the growth of algae. The chlorine vaporizes quickly, producing an unpleasant odor. To maintain proper chlorine levels, daily replenishment is required. This can be very expensive and troublesome. Consequently, many pool owners often fail to maintain sufficient chlorine levels to suppress algae and bacteria growth, necessitating frequent cleaning of the pool and creating a health hazard to pool users.
Maintaining the cleanliness of toilet bowls is another difficult problem. Fecal matter and urine contaminate the bowl and provide a fertile feed stock for bacteria therein. If a toilet bowl is not cleaned frequently, a scum develops within the bowl below the water line. This scum includes coliform and other bacteria and varieties of algae that require little or no light in which to grow. Conventionally, toilet bowls are frequently scrubbed and disinfected to eliminate the scum build up and to kill the bacteria and other microorganisms that grow in the bowl. Another approach has been to try to prevent the build up of scum or the growth of bacteria by adding chlorine to the toilet bowl water. One such device, containing stabilized, solidified chlorine, is immersed in the toilet reservoir to dissolve chlorine into the toilet water. However, such devices are relatively short lived, six months at most. Thus, their continued use over an extended period of time can become rather expensive.
Certain metal compounds, such as copper sulfate, are known to have biocidal characteristics. Copper sulfate powders have been used on roof tops to kill moss. Copper sulfate crystals have also been dissolved in bodies of water such as ponds or lakes to curtail the growth of algae. However, the copper sulfate quickly dissolves into the water and then dissipates as the water in the pond is replaced by additional water. It also does not appear that copper sulfate or similar compounds can be used safely in swimming pools or other bodies of water in quantities sufficient to kill algae and coliform bacteria and yet safe for human use. It is unknown whether copper sulfate has ever been tried in toilets. However, it is apparent that the copper sulfate, if so used, would have to be replenished each time the toilet is flushed. It would be preferable to have a device that would continually act to kill algae and bacteria over a long period of time without having to be replenished and without endangering users of the water.
S. L. Rapaport has previously proposed, in U.S. Pat. Nos. 3,479,130 and 3,494,727, the use of two metals, such as copper and lead, on roof tops to inhibit microbial or fungal growths which darken roof tops in semi-tropical and tropical climates. An electrolytic action results when rainwater contacts the metals to dissolve metal ions and thereby create a solution which kills the microbes and fungus. However, Rapaport does not disclose the use of elemental metals in swimming pools, toilet bowls or other bodies of water. Nor does Rapaport disclose use of such metals to kill algae or coliform bacteria in toilets or swimming pools. Therefore, there remains a need for a means for killing microorganisms in bodies of water without rendering the water unsafe for human use.